enhance api endpoints that provide autocomplete backend for table permission forms #1507:

- Implement similarity search via db extension
- endpoints for groups & users

Author: jh-RLI

api/views.py

@@ -11,10 +11,13 @@
 import sqlalchemy as sqla
 import zipstream
 from django.contrib.auth.mixins import LoginRequiredMixin
+from django.contrib.postgres.search import TrigramSimilarity
 from django.core.exceptions import PermissionDenied
 from django.db.models import Q
 from django.db.utils import IntegrityError
 from django.http import Http404, HttpResponse, JsonResponse, StreamingHttpResponse
+from django.core.serializers import serialize
+
 from omi.dialects.oep.compiler import JSONCompiler
 from omi.structure import OEPMetadata
 from rest_framework import status
@@ -715,10 +718,10 @@ def get(self, request, schema, table, row_id=None):
                 content_type="text/csv",
                 session=session,
             )
-            response[
-                "Content-Disposition"
-            ] = 'attachment; filename="{schema}__{table}.csv"'.format(
-                schema=schema, table=table
+            response["Content-Disposition"] = (
+                'attachment; filename="{schema}__{table}.csv"'.format(
+                    schema=schema, table=table
+                )
             )
             return response
         elif format == "datapackage":
@@ -746,10 +749,10 @@ def get(self, request, schema, table, row_id=None):
                 content_type="application/zip",
                 session=session,
             )
-            response[
-                "Content-Disposition"
-            ] = 'attachment; filename="{schema}__{table}.zip"'.format(
-                schema=schema, table=table
+            response["Content-Disposition"] = (
+                'attachment; filename="{schema}__{table}.zip"'.format(
+                    schema=schema, table=table
+                )
             )
             return response
         else:
@@ -1133,20 +1136,78 @@ def get(self, request):
         return HttpResponse("All connections closed")
 
 
+# def get_users(request):
+#     string = request.GET["name"]
+#     users = login_models.myuser.objects.filter(
+#         Q(name__trigram_similar=string) | Q(name__istartswith=string)
+#     )
+#     return JsonResponse([user.name for user in users], safe=False)
+
+
 def get_users(request):
-    string = request.GET["name"]
-    users = login_models.myuser.objects.filter(
-        Q(name__trigram_similar=string) | Q(name__istartswith=string)
-    )
-    return JsonResponse([user.name for user in users], safe=False)
+    query = request.GET.get("name", "")
+
+    # Ensure query is not empty to proceed with filtering
+    if query:
+        users = (
+            login_models.myuser.objects.annotate(
+                similarity=TrigramSimilarity("name", query),
+            )
+            .filter(
+                Q(similarity__gt=0.2) | Q(name__istartswith=query),
+            )
+            .order_by("-similarity")[:6]
+        )
+    else:
+        # Returning an empty list.
+        users = login_models.myuser.objects.none()
+
+    # Convert to list of user names
+    user_names = [user.name for user in users]
+
+    return JsonResponse(user_names, safe=False)
+
+
+# def get_groups(request):
+# string = request.GET["name"]
+# users = login_models.Group.objects.filter(
+#     Q(name__trigram_similar=string) | Q(name__istartswith=string)
+# )
+# return JsonResponse([user.name for user in users], safe=False)
 
 
 def get_groups(request):
-    string = request.GET["name"]
-    users = login_models.Group.objects.filter(
-        Q(name__trigram_similar=string) | Q(name__istartswith=string)
+    """
+    Return all Groups where this user is a member that match
+    the current query. The query is input by the User.
+    """
+    try:
+        user = login_models.myuser.objects.get(id=request.user.id)
+    except login_models.myuser.DoesNotExist:
+        raise Http404
+
+    query = request.GET.get("name", None)
+    if not query:
+        return JsonResponse([], safe=False)
+
+    user_groups = user.memberships.all().prefetch_related("group")
+    groups = [g.group for g in user_groups]
+
+    # Assuming 'name' is the field you want to search against
+    similar_groups = (
+        login_models.Group.objects.annotate(
+            similarity=TrigramSimilarity("name", query),
+        )
+        .filter(
+            similarity__gt=0.2,  # Adjust the threshold as needed
+            id__in=[group.id for group in groups],
+        )
+        .order_by("-similarity")[:5]
     )
-    return JsonResponse([user.name for user in users], safe=False)
+
+    group_names = [group.name for group in similar_groups]
+
+    return JsonResponse(group_names, safe=False)
 
 
 def oeo_search(request):